<b>Peripheral Blood:</b> 5 mL in EDTA tube.<br>
<b>Note:</b> Test is RNA-based. Please select Extract & Hold - RNA if specimen hold service is desired.</p>
Positive results identify the isoform and quantify it as a ratio with the amount of transcript from a normal control gene. Analytical sensitivity is 1 tumor cell in 10,000 normal cells.</p>
The t(15;17) translocation results in the expression of a chimeric mRNA, PML-RARA; which is considered diagnostic for acute promyelocytic leukemia (APL). Two major forms of this fusion transcript have been described, long and short. Identification of these fusion transcripts is essential in APL because it is closely correlated with responsiveness to treatment with all-trans retinoic acid or other specific therapy which substantially improves survival of patients with the disease.
Presence of this abnormality in AML is associated with excellent outcome. This assay is recommended for confirmation of diagnosis and for monitoring minimal residual disease (MRD) and predicting relapse. For monitoring MRD, we recommend monitoring trend rather than making conclusion based on one measurement.